Inserting Unicode in Emacs
This was a very nice surprise; I've never seen anything like it in any other editor.
To insert a Unicode character, use C-x 8 RET. An interactive menu will appear where you can search for the character you want by name.
For example, the command:
C-x 8 RET BANKNOTE WITH EURO SIGN RET

...inserts the 💶 character into the buffer:
Mind blowing... 🤯🤯🤯